Antibodies to the Triplet Codons AAA, AAC, and AUG: Reactions with Nucleic Acids

Abstract

Antibodies specific for the trinucleotide codons AAA, AUG, and AAC were examined for their reactions with nucleic acids. Anti-AUG and anti-AAC precipitated denatured DNA. Anti-AAA did not, and moreover, the binding of a tritiated AAA derivative to anti-AAA was not inhibited by denatured DNA. Radioligand-binding studies showed that anti-AAA was highly specific for the triplet sequence, some cross-reactions occurring with di-A and tetra-A but little with A and poly(A). The anti-codons did not precipitate whole yeast RNA, but binding could be demonstrated with Escherichia coli ³H-rRNA. Anti-AAC and anti-AUG (but not anti-AAA) bound E. coli ¹⁴C-tRNA. Anti-AUG was found to inhibit protein synthesis in an in vitro system in which rabbit reticulocyte mRNA was being translated. Inhibition was abolished by absorption of the antibody with AUG-RSA. The results of these and previous experiments (reference 1) are interpreted to indicate that antibodies can recognize trinucleotide sequences but not with absolute specificity, and it is suggested that antibodies to longer nucleotide sequences might show specificity comparable to that shown by antibodies to polysaccharide and peptide sequences.